1. Field of the Invention
The present invention relates to an electrical connector for electrically connecting an electronic package such as a central processing unit (CPU) with a circuit substrate such as a printed circuit board (PCB), and particularly to an electrical connector having an operation lever accurately and safely positioned at respective limits of its range of movement.
2. Description of Prior Art
Electrical connectors ate widely used in personal computer (PC) systems for electrically connecting electronic packages such as CPUs with circuit substrates such as PCBs. Typical such electrical connectors are known as CPU sockets. A typical CPU socket comprises a base soldered to and electrically connected with the PCB, a cover slidably mounted on the base and having a CPU attached thereon, and an actuation device for actuating the cover to slide along the base.
The CPU has a multiplicity of pins depending from a bottom surface thereof and arranged in a rectangular array. The cover of the CPU socket has a multiplicity of through holes arranged in a rectangular array corresponding to the pins of the CPU. The base of the CPU socket has a multiplicity of passageways arranged in a rectangular array and also corresponding to the pins of the CPU. Each passageway receives an electrical terminal therein.
In use, the CPU is attached to the CPU socket. The pins of the CPU extend through the corresponding through holes of the cover and are received in the corresponding passageways of the base. The pins of the CPU do not contact the corresponding electrical terminals. Thus the CPU is attached with zero insertion force. That is, the pins of the CPU are prevented from being flexed by sudden force being applied thereto by the electrical terminals. Then, the actuation device actuates the cover to slide along the base. When the cover reaches a closed position with respect to the base, the actuation device pushes the pins of the CPU into mechanical and electrical engagement with the corresponding electrical terminals.
This kind of conventional CPU socket is detailed in xe2x80x9cDevelopment of a ZIF BGA Socketxe2x80x9d (Connector Specifier Magazine, May 2000, pp.16xcx9c18). Similar kinds of CPU sockets are also disclosed in Taiwan Patent Issue Nos. 394472, 481375, 481378, 443622 and 462542.
Taiwan Patent Issue Nos. 394472, 481375, 481378, 443622 and 462542 each disclose a CPU socket comprising an actuation device positioned between a base and a cover. The actuation device comprises a camshaft for actuating the cover to slide along the base, and an operation lever extending perpendicularly from one end of the camshaft to facilitate manual handling by a user. When the CPU is attached on or removed from the CPU socket, the operation lever is rotated upwardly to a position perpendicular to the base. In this process, the operation lever is prone to be accidentally over-rotated beyond said perpendicular position. When this happens, the CPU socket may be damaged. Furthermore, when the CPU is to be engaged with terminals of the base, the operation lever is rotated downwardly to a position parallel to the base. In this process, the operation lever is prone to be accidentally over-rotated beyond said parallel position. When this happens, the CPU socket may be damaged.
A new electrical connector that overcomes the above-mentioned disadvantages is desired.
Accordingly, an object of the present invention is to provide an electrical connector for electrically connecting an electronic package such as a CPU with a circuit substrate such as a PCB, whereby the electrical connector is configured so that an operation lever thereof can be accurately and safely positioned at respective limits of its range of movement.
To achieve the above-mentioned object, an electrical connector in accordance with a preferred embodiment of the present invention is for electrically connecting a CPU with a PCB. The electrical connector comprises a generally rectangular insulative base, a cover slidably attached on the base, and an actuation device for actuating the cover to slide along the base.
The actuation device comprises a camshaft and an operation lever. The camshaft is rotatably positioned between the base and the cover, and defines a locating recess therein. The operation lever extends perpendicularly from one end of the camshaft and is positioned substantially outside the base and the cover, to facilitate manual handling by a user. The base comprises a main portion, and a front portion integrally extending from the main portion. The main portion defines a multiplicity of receiving passageways arranged in a rectangular array. Each passageway receives an electrical terminal therein, and the electrical terminals are electrically connected with the PCB. The front portion defines an engaging surface for engaging with the cover. A locating slot is defined at the engaging surface, rotatably locating the camshaft of the actuation device therein. The front portion forms a locating block in the slot. The locating block engages with the camshaft at the locating recess, to help prevent the operation lever from being over-rotated in either of opposite directions.